A typical form of safety belt assembly for a vehicle seat comprises a safety belt webbing which can be pulled out of a belt retractor and which is provided with a fixing element. The belt retractor is fixed at one side of the vehicle seat while an engagement element for receiving the fixing element on the belt webbing is mounted at the second side of the vehicle seat. A vehicle seat with safety belt assembly of that kind is to be found in German laid-open application (DE-OS) No 2 236 128. In that case the fixing element on the safety belt is formed by a tongue member while the engagement element provided for retainingly receiving the fixing element is formed by a belt lock for the tongue member. Insertion of the tongue member into the belt lock, which requires a push-in engagement movement, involves those two components being precisely guided relative to each other, which however is possible only by using two hands. That relatively complicated procedure often means that the occupant of the seat does not bother to fit the safety belt. That however is extremely dubious and potentially dangerous from safety points of view.
German laid-open application (DE-OS) No 1 964 123 discloses a vehicle seat with a safety belt assembly comprising a safety belt having a fixing element in the form of a spring hook device which can be latchingly engaged into an associated engagement element. A spring hook device of that kind can also be referred to as a carabiner device. In that arrangement however the safety belt is yieldingly flexible over its entire length between fixing points on the vehicle and the spring hook device, and such flexibility makes itself felt in terms of handling of the safety belt, that is to say handling thereof when engaging the spring hook device into the engagement element.
German patent specification No 1 057 476 discloses a release device for harness belt straps in a vehicle. That release device is characterised by a pin which is arranged displaceably transversely with respect to the longitudinal direction of the vehicle and which is moved outwardly due to the force of a spring until encountering an abutment. At the outer end the pin has a knob with rounded surface for actuation by the door of the vehicle in such an arrangement that the pin is pushed back against the force of the spring when the vehicle door is closed and passes with a portion of the pin into a space defined by two lugs, and with that pin portion serves as a counterpart member for co-operation with an engagement member, preferably in the form of a spring hook device, at one end of the harness strap. The other end of the harness strap is secured to the vehicle seat or is fixed in position in the proximity of the vehicle seat. On the other hand, when the vehicle door is opened, the pin which is pushed outwardly by the spring releases the engagement member of the belt. This also involves a harness strap which is flexible between spring hooks at the ends thereof.
German published specification (DE-AS) No 1 231 123 describes a vehicle seat in combination with a safety belt assembly. In that case however the safety belt is not fixed to the vehicle seat but to the vehicle itself. That safety belt which is specific to the respective vehicle involved is provided with a spring hook device which can be fixed to an engagement member by hooking engagement therewith. Between the fixing locations and the spring hook device that safety belt is also flexibly yielding over its entire length.